Réaction #5633

Équation de réaction

resorcinol

KOH

KOH

KOH

1,8-dibromooctane

→

product

Rendement 27.0%

1,8-BIS(3-HYDROXYPHENOXY)OCTANE

Rendement 27.0%

Solvants

water

water

water

Conditions de réaction

Traitement

1. 1
   AutreA five neck five liter round bottom flask equipped with a mechanical stirrer
2. 2
   Autretwo condensers, and a dropping funnel is purged with nitrogen
3. 3
   TempératureThe easily stirable reaction mass is slowly heated
4. 4
   Températureto reflux under a slow nitrogen
5. 5
   Autrepurge
6. 6
   Températureat reflux under a nitrogen blanket over a period of two hours
7. 7
   workup.DISSOLUTIONthe reaction mass has dissolved to light tea colored solution
8. 8
   Températureit becomes increasingly clouded as salt
9. 9
   Autreis formed
10. 10
    workup.ADDITIONhas been added
11. 11
    AutreThe reaction is quenched with 1.5 liters of water
12. 12
    AutreThe reaction mixtures
13. 13
    Filtrationfiltered
14. 14
    Autreto recover a tan colored solid which
15. 15
    Lavageto wash out resorcinol and KBr
16. 16
    FiltrationThe cooled slurry is then filtered
17. 17
    Autre350 grams of crude product is recovered
18. 18
    AutreCrystallization from 400 ml acetone yield 170 grams white crystals, 88%
19. 19
    Autrepure by HPLC peak area, and recrystallization from 500 ml acetone

Mode opératoire

A five neck five liter round bottom flask equipped with a mechanical stirrer, two condensers, and a dropping funnel is purged with nitrogen then charged under a nitrogen blanket with 1.6 kg (14.5 moles) resorcinol, 160 grams deionized water, and 296.7 grams (1.091 moles) 1,8-dibromooctane. The easily stirable reaction mass is slowly heated to reflux under a slow nitrogen purge. A solution of 181 grams (2.74 moles) 85% KOH pellets in 184 grams water is added dropwise at reflux under a nitrogen blanket over a period of two hours. After about 25% of the KOH has been added, the reaction mass has dissolved to light tea colored solution then it becomes increasingly clouded as salt is formed. The reaction mixture is refluxed an additional hour after all the KOH has been added. The pH of the reaction mixture is basic. The reaction is quenched with 1.5 liters of water and acidified with 40% sulfuric acid. The reaction mixtures is then poured into 4 liters of water, cooled in an ice bath to a temperature of 10° C. and filtered to recover a tan colored solid which is slurried in 1.2 liters boiling water to wash out resorcinol and KBr. The cooled slurry is then filtered and 350 grams of crude product is recovered. Crystallization from 400 ml acetone yield 170 grams white crystals, 88% pure by HPLC peak area, and recrystallization from 500 ml acetone yields 97.4 grams product of 96% purity by HPLC peak area and high purity by gel permeation chromatography (m.p. 78°-82° C.).

Source